Meandros Med Dent J Original Article / Özgün Araştırma Nitrous Oxide Effects the Uptake of Sevoflurane to the Body During Induction İndüksiyon Sırasında Vücuda Sevofluran Alımına Nitröz Oksitin Etkisi Kamil Varlık Erel1, Feray Gürsoy1, İbrahim Kurt1, Ayşe Gürel2
1Adnan Menderes University Faculty of Medicine, Department of Anesthesiology and Reanimation, Aydın, Turkey 2Bayındır Hospital Söğütözü, Clinic of Anesthesiology and Reanimation, Ankara, Turkey
Abstract
Objective: To determine the effects of nitrous oxide (N2O) on the speed and quality of the uptake process of sevoflurane during inhalation induction in adult patients. Materials and Methods: For randomized controlled study, eighty-four American Society of Anesthesiologists I-II patients undergoing gynecological interventions were
randomly assigned to receive an 8% sevoflurane mixture with either 67% N2O plus 33% oxygen [Group sevoflurane and nitrous oxide (SA)] or 100% oxygen only [Group sevoflurane (S)]. Both groups were induced by a single-breath induction. End-tidal and inspiratory concentrations of respiratory and anesthetic gasses were continuously assessed during induction as well as time to loss of eyelash reflex, time to cessation of eye movements, and time to initiation of spontaneous breaths. Patients were intubated by the 5th minute of induction and their vital signs, bispectral indexes, reflex responses Keywords to intubation and additional drug requirements for intubation were also recorded. Second gas effect, nitrous oxide, sevoflurane, Results: End-tidal sevoflurane concentrations and the ratio of alveolar to inspiratory nd single breath induction sevoflurane concentrations (FA/Fi) of patients in group SA recorded at the 2 , the third and the 5th minute of induction showed statistically significant increases Anahtar Kelimeler when compared with patients in group S. Time to loss of eyelash reflex and time to İkinci gaz etkisi, nitröz oksit, sevofluran, tek cessation of eye movements were found to be decreased in group SA by 25 and 13%, soluk indüksiyonu respectively. Patients who presented with a reflex response to intubation in group S exceeded patients in group SA by 38.8% and patients who required additional medication for intubation in group S exceeded patients in group SA by 28.6%. Received/Geliş Tarihi : 20.12.2017 Conclusion: The findings of this study support the view that administration of 2N O Accepted/Kabul Tarihi : 12.02.2018 improves the rate and quality of mask induction with sevoflurane. The benefits
provided by N2O attributable to the concentrating and second gas effects appear doi:10.4274/meandros.79664 during the first few minutes of induction (2nd, 3rd, and 4th minutes) as well as during intubation when sevoflurane is used for mask induction. Address for Correspondence/Yazışma Adresi: Kamil Varlık Erel MD, Adnan Menderes University Faculty of Öz
Medicine, Department of Anesthesiology and Amaç: İnhalasyon indüksiyonu sırasında azot protoksit gazının (N2O) sevofluranın Reanimation, Aydın, Turkey vücuda alınması sürecinin hızı ve kalitesi üzerindeki etkilerini araştırmaktır. Phone : +90 532 443 92 02 Gereç ve Yöntemler: Jinekolojik müdahale yapılması planlanan Amerikan E-mail : [email protected] Anestezistler Derneği kriterlerine göre I-II grubunda 84 kadın hasta randomize ORCID ID: orcid.org/0000-0003-3797-483X edilerek iki gruba ayrıldı. Tek soluk indüksiyonu yöntemi ile anestetize edilen hastalarda birinci gruba [Grup sevoflurane and azot protoksit (SA)] indüksiyonda %8 sevofluran, %67 azot protoksit ve %33 oksijen, ikinci gruba [Grup sevofluran (S) © Meandros Medical and Dental Journal, Published by Galenos Publishing House. ve azot protoksit] %8 sevofluran ve %100 oksijen uygulandı. İndüksiyon sırasında This is article distributed under the terms of the oksijen, karbondioksit ve sevofluranın end-tidal ve inspiratuvar yoğunlukları, Creative Commons Attribution NonCommercial 4.0 International Licence (CC BY-NC 4.0). kirpik refleksinin kaybolmasına kadar geçen süre, gözlerin orta hatta gelmesi
64 Meandros Med Dent J 2018;19:64-70 Erel et al. Effects of Nitrous Oxide on Sevofluran 65 için geçen süre ve spontan solunumun başlaması için geçen süre kaydedildi. Hastalar indüksiyonun 5. dakikasında entübe edildi ve entübasyondaki vital bulguları, bispektral indeks değerleri, entübasyona verdikleri refleks yanıt ve ek ilaç gereksinimleri de kaydedildi. Bulgular: İndüksiyonun 2., 3., ve 4. dakikasında grup SA’daki end-tidal sevofluran konsantrasyonları ve alveoler sevofluran yoğunluğunun inspiratuvar sevofluran yoğunluğuna oranları, grup S’ye göre daha yüksekti ve aradaki fark istatistiksel olarak anlamlıydı. Grup SA’da kirpik refleksinin kaybolması için geçen süre %25, ve gözlerin orta hatta gelmesi için geçen süre %13 oranında kısalmış olarak bulundu. Entübasyona refleks cevabı olan hasta yüzdeleri grup SA’da %25, grup S’de %63,8, entübasyona ek ilaç gereksinimi olan hasta yüzdesi grup SA’da %13, grup S’de %41,6 olarak saptandı. Sonuç: Bu bulgular, sevoflurana azot protoksit eklenmesinin maskeyle anestezi indüksiyonunun hızını ve kalitesini artırdığı görüşünü destekler niteliktedir. Azot protoksitin konsantrasyon ve ikinci gaz etkisine atfedilen bu yararlar anestezi indüksiyonunun 2., 3. ve 4. dakikasında ve entübasyonda belirgin hale gelmektedir.
Introduction arterial blood pressure (DAP) above 100 mmHg], hypotensive patients (SAP below 90 mmHg), who had Nitrous oxide (N O) is frequently used during 2 bleeding diathesis, who were mentally retarded and mask induction. It was reported that the addition uncooperative, who had stated that she could not of N O during induction was beneficial due to the 2 hold her breath, who were claustrophobic, and who concentration and second gas effects (1-3). The were considered to encounter ventilation difficulties second gas effect of N O was identified for the first 2 during mask ventilation were excluded from the study. time in the study conducted by Epstein et al. (1). Midazolam intramuscular injection was Besides, the second gas effect has also been shown administered at a dose of 0.07 mg/kg 30 minutes in the studies performed with mask induction in before the operation in all patients for premedication. children. The addition of N O to induction in children 2 Patients were taken to the operating room following has been demonstrated to be beneficial in numerous insertion of the intravenous line at the dorsum studies (2-4). However, in adults, this situation has of the left hand with a 20G cannula. Monitoring not been clearly demonstrated, and there are also of electrocardiography (DII lead), heart rate (HR), publications reporting that it was not useful (5-7). noninvasive arterial pressure, tissue oxygen saturation We designed this study to investigate the speed and (SpO2), and anesthetic gasses were performed by using quality of the uptake process of sevoflurane when Datex Engstrom AS/3 (Helsinki, Finland) anesthesia administered together with N O during inhalation 2 device and monitor. Anesthetic gas monitoring was induction in adults. performed by the infrared spectrometry method Materials and Methods (sidestream method) on both the inspiration and expiration. Eighty-four American Society of Anesthesiologists Datex Engstrom AS/3 (Helsinki, Finland) anesthesia (ASA) I-II female patients who were planned to device, anesthesia circuit, 2L anesthesia balloon, and undergo gynecological interventions were included in face mask suitable for the patient’s face were used the study following approval of the Adnan Menderes during the study. A respiratory gas measurement line University Medical Faculty Ethics Committee (decision (capnometer line) was placed over the mask for gas 1, protocol number: 00008, chairman: Prof. Dr. U. measurements during the ventilation of the patient. Katkıcı, date of approval on 10 January 2002) and Patients were divided into two groups according to obtaining the informed consents of the patients. The the induction method that would be used by tossing a patients were informed about the workup during the coin for each patient; the group in which sevoflurane preoperative evaluation and the anesthesia induction and N2O would be used in combination (group SA, with the single-breath technique. Patients who were n=44) and the group that only sevoflurane would be planned to undergo emergency operation, who were utilized (group S, n=40). The system was filled with under 20 or over 60 years of age, who had cardiac 8% sevoflurane, 67%2 N O (4 L/min), 33% oxygen problems and arterial hypertension [systolic arterial (2 L/min) in group SA and with 8% sevoflurane and blood pressure (SAP) above 160 mmHg, diastolic 100% oxygen (6 L/min) in group S. The system was
Meandros Med Dent J 2018;19:64-70 66 Erel et al. Effects of Nitrous Oxide on Sevofluran
Statistical Analysis considered ready when Fi sevoflurane was read as 8% on the anesthesia monitor. While the system was Statistical analysis was performed by the “SPSS being filled, the patient was requested to perform 9.0 for Windows (SPSS Inc., Chicago, Illinois) software vital-capacity breathing twice in the room air (a package. The “a priori” calculations with G*Power 3, deep breathing exercise). HR, SAP, DAP, mean arterial based on the data of the pilot study that we conducted pressure (MAP) SpO2, and bispectral index (BIS) values at the beginning of the study, revealed that the number were recorded before initiation of anesthesia. The of the patients should be 64 in order to accurately anesthesia mask was placed on the patient’s face so identify the 10% difference in ETsev concentration as not to leak, and the chronometer was started. The (power of the study 90%) at two minutes between the patient was requested to take and hold a deep breath. two groups. The number of subjects was calculated to After placement of the face mask, the eyelash reflex be at least 40 to be able to accurately identify the 30% disappearing time (ERDT) and the time for the eyes difference in ERDT (the powerof the study 90%). to be fixed at the midline were checked at 10-second intervals and recorded. The apnea periods were Results recorded. When the spontaneous breathing of the Eighty-four ASA I-II female patients who were patients started, their respirations were supported scheduled to undergo gynecological intervention as the end-tidal carbon dioxide (ETCO2) value would were included in the study. However, ventricular be 35-40 mmHg. The patients whose breathing had extrasystole with a 2:1 response developed in one not returned within 90 seconds were ventilated by patient and bronchospasm in another. Mask induction mask and anesthesia balloon as their ETCO would be 2 could not be performed due to the fall of the SpO2 35-40 mmHg. HR, SAP, DAP, MAP, SpO2, the oxygen level below 90% in one patient, and due to the concentration in the inspiratory air, the nitrous oxide development of the cough reflex in another. These concentration in the inspiratory air (FiN2O), the four patients, who were in the group that sevoflurane sevoflurane concentration in the inspiratory air (Fisev), was administered only, were excluded from the study end-tidal oxygen concentration (ETO2), end-tidal and necessary interventions were made. nitrous oxide, end-tidal sevoflurane (ETsev), ETCO2 No statistically significant differences were and BIS values were recorded at 1-minute intervals. determined between the patient groups with regard Both patient groups were ventilated for five minutes to age and body mass index (p>0.05) (Table 1). with gas concentrations specific to their group. At Significant differences were found between the the fifth minute, the patients were intubated with groups with regard to ERDT and the time for the eyes 7.5 mm ID endotracheal tube. The reflex responses to be fixed at the midline (p<0.01). While the ERD to intubation and the requirement for additional in 59.9±25.8 seconds in group SA, it disappeared in medication during intubation were recorded. An 78.0±24.1 seconds in group S. The time for the eyes increase of more than 10% in HR and MAP over the to be fixed at the midline was 207.3±52 seconds in latest measurement, together with movements and group SA, whereas it was determined as 236.9±43.5 straining during intubation were considered as the seconds in group S (p<0.01). No statistically significant reflex response to intubation. When this reaction difference was found between the groups regarding was present, one microgram/kg i.v. Fentanyl was the duration of apnea (p>0.05) (Figure 1). administered to the patient. If the response was not The ET concentrations of sevoflurane were suppressed despite such a fentanyl dose, lidocaine 1.5 3.5±0.74% in group SA, and 3.3±0.62% in group S at mg/kg i.v. was administered together with fentanyl Table 1. The comparison of the groups regarding age one microgram/kg. Intravenous muscle relaxant and body mass index (vecuronium 0.1 mg/kg) was administered to the Group SA n=44 Group S n=36 patients encountering bronchospasm during or after Age 41.1± 9.6 42.3±8.4 intubation. Other drugs required and administered BMI 26.5± 3.2 25.6±2.8 following the first intubation were recorded as the The data were shown as the mean ± standard deviation. SA: Sevoflurane and nitrous oxide, S: Sevoflurane, BMI: Body mass index additional medications for intubation.
Meandros Med Dent J 2018;19:64-70 Erel et al. Effects of Nitrous Oxide on Sevofluran 67 the 1st minute, 4.1±0.59% in group SA and 3.7±0.67% at Discussion the 2nd minute, 4.8±0.56% in group SA and 4.3±0.71% In this study, it was determined that the addition in group S at the 3rd minute, 5.2±0.48% in group SA of N O to the single-breath induction with sevoflurane and 4.8±0.71% in group S at the 4th minute, 5.8±0.5% 2 had accelerated the anesthesia induction, had in group SA and 5.3±0.72 in group S at the 5th minute. shortened the duration to reach the surgical Although there were differences in favor of group SA anesthesia stage and had facilitated endotracheal at the first and fifth minutes, there was no statistically intubation without administering muscle relaxant. significant difference between the two groups In the N2O-added group, the eyelash reflex regarding the sevoflurane values (p>0.05). However, disappearance time and the duration for the eyes to significant differences were found on thend 2 , 3rd, and 4th minutes between the two groups regarding ETsev values (p<0.01) (Figure 2). Similar results with the ETsev comparisons were obtained when the minute FA/Fi measurements of sevoflurane were compared between the groups
(ETsev concentrations were considered as FAsev).
Statistically significant increases inFA/Fi values were determined at the 2nd, 3rd, and 4th minutes, when the
N2O added group was compared to the group that it was not supplemented, (p<0.01). These values were higher in the N2O-supplemented group at the first and 5th minutes, although not statistically significant Figure 2. End-tidal sevoflurane-time graph (p>0.05) (Figure 3). ETsev: End-tidal sevoflurane concentration, SA: Sevoflurane and nitrous oxide, S: Sevoflurane, *p<0.01 No statistically significant difference was found between the two groups regarding the BIS values (p>0.05) (Table 2). Data were shown as the mean ± standard deviation. There were statistically significant differences between the two groups in favor of group SA regarding the reflex response to intubation and additional medication needed for intubation (p<0.01) (Table 3). There were no significant differences between the two groups regarding HR, SAP, MAP, and SPO2 values. These values were observed to be stable. Figure 3. The increase in the alveolar concentration of sevoflurane
FA/Fi: The ratio of the anesthetic concentration to the inspiratory anesthetic concentration, SA: Sevoflurane and nitrous oxide, S: Sevoflurane, *p<0.01 Table 2. The Bispectral index values BIS Value Group SA n=44 Group S n=36 0 minimum 96±1.7 95±3.9 1st minimum 89±12.3 87±12.1 2nd minimum 55±22.4 62±19.5 3rd minimum 41±17.7 45±17.4 Figure 1. The eyelash reflex disappearance time, the time for 4th minimum 33±13.2 36±12.1 the eyes to be fixed at the midline and the duration of apnea 5th minimum 35±13.1 36±11.9 ERDT: Eyelash reflex disappearance time, TEFM: The time forthe th eyes to be fixed at the midline SA: Sevoflurane and nitrous oxide, S: 6 minimum 42±16.7 41±13.2 Sevoflurane, *p<0.01 BIS: Bispectral index, SA: Sevoflurane and nitrous oxide, S: Sevoflurane
Meandros Med Dent J 2018;19:64-70 68 Erel et al. Effects of Nitrous Oxide on Sevofluran
Table 3. The reflex response to intubation the FA/Fi ratio and arterial blood concentration did
and additional medications needed for not show any difference with the addition2 ofN O intubation to enflurane in the first five minutes; they claimed Group SA Group S chi-square that the second gas effect is not a clinically valid n=44 n=36 concept. When Mutoh et al. (15) compared the dog Reflex response Present 11 23 p<0.01* groups in which N O was added and was not added to intubation 2 Absent 33 13 to sevoflurane and isoflurane, they determined that Additional Present 6 15 p<0.01* N O had not improved the quality of mask induction medications for Absent 38 21 2 intubation and that the concentration and second gas effects *Statistically significant difference, SA: Sevoflurane and nitrous oxide, had been minimal. Regarding desflurane, Taheri and S: Sevoflurane Eger (16), in their study comparing 65% N2O and 5% N O, determined that desflurane increased the F /F come to the midline were determined to be reduced by 2 A i 25% and 13%, respectively. Muzi et al. (8), in the study ratio 7-8% more. Nishikawa et al. (17), in their study investigating the second gas effect of N O on oxygen, that they conducted in adults, found a similar result 2 found elevations in EtO and PaO values with N O for ERDT. Yurino et al. (9) determined that nitrous 2 2 2 oxide had shortened the induction time by 15%; and claimed that this result confirmed the second gas however, they were not able to prove this statistically. effect. Swan et al. (18), in a similar study, determined that N O reduced the NAC value of halothane by 40%. Hall et al. (10) suggested that the addition of nitrous 2 oxide does not shorten the durations regarding the Dubois et al. (19) determined that the times disappearance of eyelash reflex and the relaxation of of loss of the consciousness and movements the jaw; they claimed that it reduced the excitatory were significantly shorter in the group with2 N O. response only. Lee et al. (2) determined significant Watanabe et al. (20), determined that simultaneous results related to the eyelash reflex disappearance administration of halothane and 2N O to a single lung time in the study that they had carried out in children increased the halothane uptake rate when compared with single-breath induction. to administering to both lungs in their study in The ETsev concentrations of sevoflurane and the which they ventilated the lungs separately with the double-lumen tube. They described this situation as FA/Fi ratios were determined to be 6.3% higher in average at the 2nd, 3rd, and 4th minutes in the nitrous the supramaximal second gas effect. However, Lin and Wang (21) criticized the supramaximal second oxide added group. The elevation of the ETsev concentration in a shorter time with the addition of gas effect as a non-existent phenomenon; they nitrous oxide gave us the impression that indirectly, claimed that the study conducted by Watanabe et the anesthetic concentration in the brain had also al. (20) had been designed completely wrong and risen more rapidly. Also, Sarner et al. (11), in their the data had been misinterpreted. They emphasized that comparing the single and double-lumen tubes study, determined that the duration for the ETsev to reach a concentration of 2% was reduced significantly for the administration of N2O was wrong and that the N O administered ipsilateral lung should have in the N2O-added group. 2 been compared to the ipsilateral lung that N O was The elevations in the FA/Fi ratios of the 2N O-added 2 group mean that the induction with sevoflurane is not administered, instead. Goldman (3), in his study accelerated. The inspiratory concentration of the with mask induction in children, obtained results supporting the second gas effect ofN O, together anesthetic substance (Fi), determines the alveolar 2 with its concentration effects. A similar study by concentration (FA), which affects the arterial O’Shea et al. (22) revealed no statistically significant concentration of the anesthetic (Fa), thus determining the concentration of the anesthetic in the brain difference between groups regarding the induction tissue. Also, the end-tidal alveolar concentration time. However, in that study, sevoflurane mask of the anesthetic is an indicator of the anesthetic induction was initiated at a concentration of 0.5 and concentration in the brain (12). The second gas effect was gradually increased up to a concentration of 8. was proposed by Epstein et al. (1) and was proven We think that the number of the patients should be in the consecutive study (13). However, in the study greater to detect a difference in induction time. Also, carried out by Sun et al. (14), it was determined that the concentrations of FA/Fa not been measured might
Meandros Med Dent J 2018;19:64-70 Erel et al. Effects of Nitrous Oxide on Sevofluran 69 have prevented us from determining the second gas shortens the induction period have suggested that and concentration effects. N2O accomplishes this by the second gas effect and No statistical difference was found in the the previously shown additive effects (11,18,19,30). comparison of BIS values. However, lower BIS values The opponent group has advocated in their studies nd rd th were obtained at the 2 , 3 , and 4 minutes. The that N2O does not shorten the induction period and statistical strength of the study regarding BIS values the addition of 2N O during induction is unnecessary was insufficient with these patient numbers. Further (9,10,22). However, in the studies representing both studies with increased patient numbers are needed. opinions, the excitatory and movement responses Also, when we look at the medical literature, were determined to be less in the N2O added groups. numerous studies are present showing that BIS value In both the studies suggesting that it shortens remains unchanged (23-29). There are hypotheses the induction period and the studies suggesting that there was no difference, the patient ages being that the reason of this is related to N2O changing the beta ratio in BIS (the ratio of very high beta activity to different (adult, child, infant), the differences of the the sum of high alpha and beta activities) (23). used anesthesia systems (ring system, Mapleson A, The reflex response to intubation was found as B, D), flow differences (within the range of 3 L/min. and 10 L/min.), in other words, the inability to provide 39% and the need for additional medications during a complete standardization regarding ventilation, intubation was lower by 32% in the N O added group. 2 cardiac output and lung capacities might be a cause We consider that this difference is related to both the of such different results. accelerator effect of 2N O on intubation and its strong N2O was used with the recommended dose (67%) analgesic effect. Numerous factors such as ventilation, in this study. Also, the ventilation parameters were cardiac output, lung capacities, functional residual adjusted so as to keep the ETCO2 concentration capacity, inspiratory and expiratory anesthetic constant. It was attempted to ensure that the non- concentrations, arterial and venous blood anesthetic constant factors affecting the uptake of the anesthetic concentrations (Ca and Cv) have effects on the uptake agent would be effective equally in all study groups. of volatile agents to the body. Evaluating the second The arterial concentration of the anesthetic could not gas effect of2 N O by keeping all these parameters be measured due to technical insufficiencies. constant is difficult. The data in our study were supportive of the In the study of Sun et al. (14) in which they did studies reporting that2 N O shortened the induction not accept the second gas effect, the ventilation period. Although N2O seemed to lose its advantage parameters were not kept constant, and the cardiac for the induction at theth 5 minute, which was effects of 2N O were ignored. The effects of 2N O on the observed within the first three minutes, the need for functions of the cardiovascular system are increasing more medications of the group without2 N O shows the HR and arterial blood pressure mildly, and thus the that these effects of 2N O can be benefited in a special cardiac output, by stimulating the sympathetic nervous and limited adult patient group in which i.v. induction system. This effect becomes even more pronounced cannot be performed. at higher concentrations (12). Sun et al. (14) used 2N O at high concentrations in their experimental group. Conclusion Taheri and Eger (16), criticizing this study, stated that The results of this study showed that, with the to prevent ventilatory differences and to keep the addition of2 N O, the sevoflurane induction was respiratory quotient (RQ) constant, the ventilation accelerated, and the intubation without administering parameters should be adjusted so as to keep the ETCO 2 muscle relaxant was facilitated, suggesting that 2N O concentration constant in the study groups. Since plays a significant role in the process of sevoflurane parameters related to cardiac output and respiration uptake to the body (second gas effect) in adults, also. were not kept constant during the study conducted Ethics by Sun et al. (14), their rejection of the secondary gas Ethics Committee Approval: For this study, effect is controversial. approval of Adnan Menderes University Medical The investigators have stated two different Faculty Ethics Committee (decision 1, protocol points of view related to the addition of2 N O to number: 00008, chairman: Prof. Dr. U. Katkıcı, date of sevoflurane induction. Those who defend that it approval on 10 January 2002) was taken.
Meandros Med Dent J 2018;19:64-70 70 Erel et al. Effects of Nitrous Oxide on Sevofluran
Informed Consent: Consent form was filled out by 13. Stoelting RK, Eger EI 2nd. An additional explanation for the second all participants. gas effect: a concentrating effect. Anesthesiology 1969; 30: 273-7. Peer-review: Externally peer-reviewed. 14. Sun XG, Su F, Shi YQ, Lee C. The "second gas effect" is not a valid concept. Anesth Analg 1999; 88: 188-92. Authorship Contributions 15. Mutoh T, Nishimura R, Sasaki N. Effects of nitrous oxide on mask Surgical and Medical Practice: K.V.E., Concept: induction of anesthesia with sevoflurane or isoflurane in dogs. Am J K.V.E., A.G., Design: K.V.E., A.G., Data Collection or Vet Res 2001; 62: 1727-33. Processing: K.V.E., Analysis or Interpretation: K.V.E., 16. Taheri S, Eger EI, 2nd. A demonstration of the concentration and F.G., Literature Search: K.V.E., A.G., I.K., Writing: K.V.E. second gas effects in humans anesthetized with nitrous oxide and desflurane. Anesth Analg 1999; 89: 774-80. Conflict of Interest: No conflict of interest was 17. Nishikawa K, Kunimoto F, Isa Y, Miyoshi S, Takahashi K, Morita T, et declared by the authors. al. Second gas effect of N2O on oxygen uptake. Can J Anaesth 2000; Financial Disclosure: The authors declared that 47: 506-10. this study received no financial support. 18. Swan HD, Crawford MW, Pua HL, Stephens D, Lerman J. Additive contribution of nitrous oxide to sevoflurane minimum alveolar References concentration for tracheal intubation in children. Anesthesiology 1999; 91: 667-71. 1. Epstein RM, Rackow H, Salanitre E, Wolf GL. Influence of the 19. Dubois MC, Piat V, Constant I, Lamblin O, Murat I. Comparison of concentration effect on the uptake of anesthetic mixtures: The three techniques for induction of anaesthesia with sevoflurane in second gas effect. Anesthesiology 1964; 25: 364-71. children. Paediatr Anaesth 1999; 9: 19-23. 2. Lee SY, Cheng SL, Ng SB, Lim SL. Single-breath vital capacity high 20. Watanabe S, Asakura N, Taguchi N. Supramaximal second gas effect: concentration sevoflurane induction in children: with or without more rapid rise of alveolar halothane concentration during ipsilateral nitrous oxide? Br J Anaesth 2013; 110: 81-6. lung N2O administration compared to bilateral administration. 3. Goldman LJ. Anesthetic uptake of sevoflurane and nitrous oxide Anesth Analg 1993; 76: 76-9. during an inhaled induction in children. Anesth Analg 2003; 96: 400-6. 21. Lin CY, Wang JS. Supramaximal second gas effect--a nonexistent 4. Agnor RC, Sikich N, Lerman J. Single-breath vital capacity rapid phenomenon. Anesth Analg 1993; 77: 870-2. inhalation induction in children: 8% sevoflurane versus 5% 22. O'Shea H, Moultrie S, Drummond GB. Influence of nitrous oxide on halothane. Anesthesiology 1998; 89: 379-84. induction of anaesthesia with sevoflurane. Br J Anaesth 2001; 87: 5. Ti LK, Pua HL, Lee TL. Single vital capacity inhalational anaesthetic 286-8. induction in adults--isoflurane vs sevoflurane. Can J Anaesth 1998; 23. Puri GD. Paradoxical changes in bispectral index during nitrous oxide 45: 949-53. administration. Br J Anaesth 2001; 86: 141-2. 6. Peyton PJ, Horriat M, Robinson GJ, Pierce R, Thompson BR. 24. Barr G, Jakobsson JG, Owall A, Anderson RE. Nitrous oxide does not Magnitude of the second gas effect on arterial sevoflurane partial alter bispectral index: study with nitrous oxide as sole agent and as pressure. Anesthesiology 2008; 108: 381-7. an adjunct to i.v. anaesthesia. Br J Anaesth 1999; 82: 827-30. 7. Hendrickx JF, Carette R, Lemmens HJ, De Wolf AM. Large volume 25. Porkkala T, Jantti V, Kaukinen S, Hakkinen V. Nitrous oxide has N2O uptake alone does not explain the second gas effect of N2O on different effects on the EEG and somatosensory evoked potentials sevoflurane during constant inspired ventilation. Br J Anaesth 2006; during isoflurane anaesthesia in patients. Acta Anaesthesiol Scand 96: 391-5. 1997; 41: 497-501. 8. Muzi M, Robinson BJ, Ebert TJ, O'Brien TJ. Induction of anesthesia 26. Yli-Hankala A, Lindgren L, Porkkala T, Jantti V. Nitrous oxide-mediated and tracheal intubation with sevoflurane in adults. Anesthesiology activation of the EEG during isoflurane anaesthesia in patients. Br J 1996; 85: 536-43. Anaesth 1993; 70: 54-7. 9. Yurino M, Kimura H. Comparison of induction time and 27. Ropcke H, Schwilden H. Interaction of isoflurane and nitrous characteristics between sevoflurane and sevoflurane/nitrous oxide. oxide combinations similar for median electroencephalographic Acta Anaesthesiol Scand 1995; 39: 356-8. frequency and clinical anesthesia. Anesthesiology 1996; 84: 782-8. 10. Hall JE, Stewart JI, Harmer M. Single-breath inhalation induction 28. Sebel PS, Lang E, Rampil IJ, White PF, Cork R, Jopling M, et al. A of sevoflurane anaesthesia with and without nitrous oxide: a multicenter study of bispectral electroencephalogram analysis for feasibility study in adults and comparison with an intravenous bolus monitoring anesthetic effect. Anesth Analg 1997; 84: 891-9. of propofol. Anaesthesia 1997; 52: 410-5. 29. Rampil IJ, Kim JS, Lenhardt R, Negishi C, Sessler DI. Bispectral EEG 11. Sarner JB, Levine M, Davis PJ, Lerman J, Cook DR, Motoyama EK. index during nitrous oxide administration. Anesthesiology 1998; 89: Clinical characteristics of sevoflurane in children. A comparison with 671-7. halothane. Anesthesiology 1995; 82: 38-46. 30. Sivalingam P, Kandasamy R, Dhakshinamoorthi P, Madhavan G. 12. Morgan GE, Michael SM, Murray JM. Inhalational Anesthetics. In: Tracheal intubation without muscle relaxant--a technique using Morgan GE, Michael SM, Murray JM, eds. Clinical Anesthesiology. 3 sevoflurane vital capacity induction and alfentanil. Anaesth ed. New York: Lange and Mc Graw Hill; 2002: 127-50. Intensive Care 2001; 29: 383-7.
Meandros Med Dent J 2018;19:64-70